|Publication number||US5848601 A|
|Application number||US 08/948,723|
|Publication date||Dec 15, 1998|
|Filing date||Oct 10, 1997|
|Priority date||Oct 10, 1997|
|Publication number||08948723, 948723, US 5848601 A, US 5848601A, US-A-5848601, US5848601 A, US5848601A|
|Inventors||Edward L. Thies|
|Original Assignee||Whirlpool Corporation|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (14), Referenced by (17), Classifications (17), Legal Events (4)|
|External Links: USPTO, USPTO Assignment, Espacenet|
1. Field of Invention
The present invention relates to a dishwasher pump and more particularly to a efficient and compact configuration for a dishwasher pump having a filtration and soil collection system.
2. Description of the Related Art
Typical domestic dishwashers in use today draw wash liquid from a sump at the bottom of a wash tub and spray the wash liquid within the wash tub to remove soils from dishes located on racks in the tub. In an attempt to improve performance and efficiency, some dishwashers employ a system for separating soil out of the recirculating wash liquid and for retaining the soils in a collection chamber. Frequently, a filter screen is used to retain soil in a soil collection chamber. U.S. Pat. No. 5,165,433, issued to Meyers, and U.S. Pat. No. 5,377,707, issued to Young, Jr., illustrate a common configuration for employing a filter screen in a dishwasher pump. In these references, the filter screen is arranged in an annular configuration in the cover of the dishwasher pump.
While filtering is an effective means for cleaning recirculating wash liquid, it is relatively costly to incorporate a filter screen into a dishwasher pump. Filter screens are typically formed from fine, synthetic mesh material, such as nylon or polyester, which is heat welded to a pump component, for forming a plurality of filter screen panels or segments. As the cost of the synthetic material is relatively high as compared to other dishwasher pump components, it is advantageous from a cost standpoint to minimize the amount of mesh used. However, in order to achieve satisfactory filter performance, the surface area of the filter screen must be sufficient to filter dishwasher wash liquid without undue clogging concerns.
In the annular filter screen configurations, as disclosed in the '433 and '707 references, the filter screen is fabricated out of rectangular sections of synthetic mesh which is then cut into the desired annular shape for incorporation in the dishwasher cover. During this fabrication process, the cut out center and corner sections are wasted. It can be readily appreciated, that for a predetermined filter screen surface area, the larger the inner diameter of the annular filter screen, the more waste material is generated in the cut out center portion and the corner portions. Accordingly, it is desirable, when designing a dishwasher pump employing an annular filter configuration, to minimize the inner diameter of the filter screen.
The '433 patent illustrates a pump which centrifugally separates wash liquid in a pump impeller cavity and supplies soil laden wash liquid to a soil container chamber. In centrifugal pump systems such as this one, it is desirable to provide a pump impeller cavity configured to aid in the centrifugal separation of soils and delivery to a soil container chamber.
Another problem to consider when designing dishwasher pump systems is water usage. Water usage is a critical concern in dishwasher operation for two reasons. Firstly, hot water usage is the principle factor in determining a dishwasher's energy performance. Secondly, conservation of water is becoming more and more of a concern in many regions of this country and the world. Accordingly, it is desirable to utilize a pump which is capable of effective operation with a minimal amount of water. In a vertical pump configuration such as shown in the patents '433 and '707, this means that it is preferable to have a pump having a minimal vertical height. In general, the shorter the pump, the less water is required for the pump to recirculate wash liquid in the dishwasher.
Accordingly, the present invention is directed to a pump system for a dishwasher including a pump housing defining a pump chamber having an inverted frustroconical shape including an upwardly angled annular outer wall. An impeller is disposed within the pump chamber. An annular soil collection chamber is disposed partially above the pump chamber such that the bottom wall of the soil collection chamber forms the top wall of the pump chamber. Wash liquid is supplied into the soil collection chamber from the pump chamber through an opening provided in the bottom wall of the soil collection chamber located at the upper, peripheral portion of the pump chamber. The upwardly angled annular wall of the pump chamber promotes soil movement into the soil collection chamber by directing soils toward the upper portion of the pump chamber. Soil is drained out of the soil collection chamber through a drain conduit having a flapper type check valve.
The soil collection chamber is formed by an annular soil collector housing and a cover which may be snap connected to the annular soil collector housing. The cover includes a plurality of filter screen panels such that wash liquid supplied into the soil collection chamber is filtered and soils are collected. By locating the collection chamber above the pump chamber, the inner diameter of the soil collection chamber may be formed smaller than the outer diameter of the pump chamber such that the outer diameter of the soil collection chamber may be minimized.
FIG. 1 is a perspective view of a dishwasher including a soil separation and collection system in accordance with the present invention.
FIG. 2 is a diametric sectional view of a dishwasher pump as illustrated in FIG. 1.
FIG. 3 is a sectional view, as taken along lines III--III of FIG. 2.
FIG. 4 is a diametric sectional view taken along line IV--IV of FIG. 3, illustrating the soil collector drain system.
In accordance with the invention as shown in the drawings, and particularly as shown in FIG. 1, an automatic dishwasher generally designated 10 includes an interior tub 12 forming an interior wash chamber or dishwashing space 14. The tub 12 includes a sloped bottom wall 16 which defines a lower tub region or sump 18 of the tub. A pump system 20, including a soil collection system, is centrally located in the bottom wall 16 and supplies wash liquid to a lower wash arm assembly 22 for recirculating wash liquid throughout the interior wash chamber. Wash liquid may also be supplied to an upper spray arm (not shown).
Turning to FIG. 2, the pump system 20 is shown in greater detail. The pump includes lower and upper assemblies 30 and 32. The lower assembly 30 includes a pump base 34 and a drain cover 36 which define a drain impeller chamber 38. A drain impeller 40 is rotatably secured to an output shaft 42 of a motor 44 suspended below the pump system.
The upper assembly 32 of the pump system includes a pump chamber 48 and an annular soil collection chamber 50. A pump housing 52, which partially defines the pump chamber 48, is secured to the pump base 34 and includes a circular wall portion 52a and an upwardly angled, annular wall portion 52b. A soil collector housing 54 is disposed above and is fastened to the pump housing 52 via threaded fasteners 56 for forming the pump chamber 48. A wash impeller 58 is supported within the pump chamber 48 and is drivingly connected to the output shaft 42 of the motor 44.
As shown in FIGS. 2 and 3, the soil collector housing 54 is formed having a flat annular wall 54a, an inner wall 54b upwardly angled from the inner peripheral edge of the flat annular wall 54a and an outer, cylindrical wall 54c extending upwardly from the outer peripheral edge of the annular bottom wall 54a. A center opening 60 is provided through the soil collector housing 54. A plurality of diffuser vanes 62 extend from the housing 54 toward the impeller 58 for generating pressure such that wash liquid is moved upwardly through the center opening 60. A pump outlet member 64 is connected to the center opening and directs wash liquid to the lower wash arm 22 and the upper wash arm of the dishwasher.
During a wash cycle, the wash impeller 58, driven by the motor 44, draws wash liquid from the sump 18 and pumps wash liquid up through a pump outlet member 64. The pump outlet member 64 may be secured to the soil collector housing 54 through use of fasteners 65. A first portion of wash liquid is sprayed from the lower wash arm 22 against dishes supported on a lower dishrack and a second portion of wash liquid may be directed toward an upper spray arm. Wash liquid is repeatedly recirculated over the dishes for removing soils therefrom.
Once soils are removed from the dishes, they are washed down into the sump 18. A chopping system may be provided for sizing soils prior to drawing them into the pump chamber 48. The basic constructional features of a chopper assembly are explained in U.S. Pat. No. 4,319,599, entitled "Vertical Soil Separator for Dishwasher", herein incorporated by reference. The use of a chopper is optional and is not necessary to practice the invention.
The soil collection chamber 50 is formed by connecting a cover 66 to the soil collector housing 54. The cover 66 is an annular member having a plurality of filter screen panels 68 (see FIG. 1). The filter screen panels 68 are formed from fine, synthetic mesh material, such as nylon or polyester, which is heat welded to the cover 66. The outer periphery of the cover 66 may preferably be snap connected to the soil collector housing 54 via snap openings 70 provided on an annular wall portion 66a of the cover 66 which engage projecting tabs 72 provided on the cylindrical wall 54c. A snap connection assembly may be used to connect the cover to the soil collector housing 54, rather than conventional use of threaded fasteners, due to the fact that the filter screen panels 68 prevent pressure built up such that the soil collection chamber is maintained at a relatively low pressure. The inner portion of the cover 66 is secured to the soil collector housing 54 by capturing an annular inner portion 66b of the cover 66 between the pump outlet 64 and the soil collector housing 54.
It can be seen, therefore, that the upper assembly 32 is configured such that the soil collection chamber 50 is disposed at an elevation above the pump chamber 48 and extends partially above the pump chamber 48. Specifically, as preferably disclosed, an inner annular portion of the soil collection chamber 54, comprising approximately half of the chamber 54, is disposed above the outer portion of the pump chamber 48, including an outermost annular portion of the wash impeller 58. This configuration, wherein the soil collection chamber is disposed partially above the pump chamber, allows for a soil collection chamber 54 having a relatively small outer diameter while maintaining a desirable filter screen area for filtering wash liquid.
As shown in FIG. 2, the soil collection chamber 50 receives soil laden wash liquid from the pump chamber 48 through opening 74 provided in the annular wall 54a. The opening 74 is located at the intersection of the upwardly angled wall 52b and the annular wall 54a at the outermost portion of the pump chamber. Soils in the pump chamber 48, due to the swirling action of the wash liquid, are urged to the outermost portion of the pump chamber by centrifugal forces such that the wash liquid supplied into the soil collection chamber is laden with soils removed from the dishes being washed. Moreover, the upwardly angled wall 52b further enhances the flow of soils into the soil collection chamber by directing the soils upwardly toward the opening 74. A deflector wall portion 76 is provided on the cover 66 opposite the opening 74 for deflecting the flow of wash liquid through the opening 74 about the soil collection chamber 50 such that soils do not become embedded into the filter screen panels.
FIG. 4 illustrates a diametric section of the pump system 20 cut through the drain system of the soil collection chamber 50. The drain system includes a drain conduit 78 extending between the soil collection chamber 50 and the drain impeller chamber 38. A flapper type valve 82 is captured between the bottom surface of the drain conduit 78 and a drain cover boss 84. The valve 82 operates as a check valve for the soil collector chamber such that during wash, the drain impeller urges the flapper valve 82 to close while during drain the flapper valve 82 opens such that soils can drain through the conduit 78 into the drain chamber 38. Accordingly, the drain cycle, the drain impeller 40 draws wash liquid out of the soil collection chamber 50 and pumps them to drain.
It can be seen, therefore, that the present invention provides for a uniquely compact and cost effective pump system including soil collection system. In particular, the pump is configured to minimize the outer diameter of the soil collection chamber, thereby minimizing the total amount of filter screen required during manufacture of the pump. Moreover, pump chamber 48 and the opening 74 for supplying wash liquid into the soil collection chamber 50 are configured to enhance soil separation and minimize assembly costs.
While the present invention has been described with reference the above described embodiment, those of skill in the Art will recognize that changes may be made thereto without departing from the scope of the invention as set forth in the appended claims.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US2862510 *||Aug 19, 1955||Dec 2, 1958||Hobart Mfg Co||Dishwasher|
|US3103225 *||Sep 29, 1960||Sep 10, 1963||Gorman Rupp Ind Inc||Dishwasher recirculating assembly|
|US3210009 *||Dec 16, 1963||Oct 5, 1965||Westinghouse Electric Corp||Dishwasher pump and filter|
|US3370598 *||Oct 20, 1965||Feb 27, 1968||Whirlpool Co||Dishwasher|
|US3432103 *||Feb 14, 1967||Mar 11, 1969||Philips Corp||Dishwasher spray apparatus with gradually increasing nozzle pressure|
|US3502090 *||Dec 14, 1967||Mar 24, 1970||Hobart Corp||Dishwashing apparatus|
|US4038103 *||Jul 27, 1976||Jul 26, 1977||Hobart Corporation||Dishwasher filter flushing system|
|US4243431 *||Jun 14, 1979||Jan 6, 1981||Whirlpool Corporation||Dishwasher soil separator|
|US4319599 *||Sep 22, 1980||Mar 16, 1982||Whirlpool Corporation||Vertical soil separator for dishwasher|
|US4392891 *||Nov 9, 1981||Jul 12, 1983||Hobart Corporation||Dishwasher soil collecting circuit|
|US4559959 *||Oct 18, 1982||Dec 24, 1985||Hobart Corporation||Dishwashing apparatus|
|US4673441 *||Dec 4, 1984||Jun 16, 1987||Meyers Theodore F||Dishwashing method|
|US5165433 *||Aug 19, 1991||Nov 24, 1992||Whirlpool Corporation||Soil separator for a domestic dishwasher|
|US5377707 *||Nov 1, 1993||Jan 3, 1995||White Consolidated Industries, Inc.||Dishwasher pump and filtration system|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US6197071 *||Oct 12, 1999||Mar 6, 2001||Eastman Kodak Company||Formulations for dyeing keratin fibers comprising a pyrazolotriazole coupler and oxidation base|
|US6615853||Jan 3, 2001||Sep 9, 2003||General Electric Company||Dishwasher fine filter pressure relief|
|US6832617||Dec 22, 2000||Dec 21, 2004||General Electric Company||Dishwasher fine filter assembly|
|US7146992 *||Jul 2, 2002||Dec 12, 2006||Maytag Corporation||Dishwasher pump and filtration system|
|US7241347||Mar 19, 2004||Jul 10, 2007||Whirlpool Corporation||Adaptive drain and purge system for a dishwasher|
|US7464720||Nov 16, 2004||Dec 16, 2008||Lg Electronics Inc.||Water recirculator in dishwasher|
|US7610923||Feb 9, 2005||Nov 3, 2009||Maytag Corporation||Pump and filter system for a drawer-type dishwasher|
|US7614409 *||Feb 10, 2005||Nov 10, 2009||Lg Electronics Inc.||Dishwasher|
|US7644718 *||Dec 7, 2005||Jan 12, 2010||Lg Electronics Inc.||Sump of dish washer|
|US7681580||Nov 13, 2008||Mar 23, 2010||Lg Electronics Inc.||Water recirculator in dishwasher|
|US8066821||Feb 9, 2005||Nov 29, 2011||Whirlpool Corporation||System for limiting pressure in a fine filter chamber for a dishwasher|
|US8449690 *||Dec 7, 2005||May 28, 2013||Lg Electronics Inc.||Sump of dish washer|
|US20040094190 *||Nov 15, 2002||May 20, 2004||Steris Inc.||Water displacement/vortex inhibiting device|
|US20040173245 *||Mar 19, 2004||Sep 9, 2004||Maytag Corporation||Adaptive drain and purge system for a dishwasher|
|US20050120533 *||Nov 1, 2004||Jun 9, 2005||Lg Electronics Inc.||Tableware washer|
|USRE37831||Jun 22, 2000||Sep 10, 2002||Whirlpool Corporation||Soil separation channel for dishwasher pump system|
|EP2503050A1 *||Mar 24, 2011||Sep 26, 2012||Electrolux Home Products Corporation N.V.||Washing machine comprising a filter element|
|U.S. Classification||134/104.4, 134/111, 134/109, 210/299|
|International Classification||F04D7/04, A47L15/42, F04D29/42|
|Cooperative Classification||F04D7/04, A47L15/4204, A47L15/4225, A47L15/4202, F04D29/426|
|European Classification||A47L15/42A, A47L15/42A2, A47L15/42C8, F04D7/04, F04D29/42P|
|Oct 10, 1997||AS||Assignment|
Owner name: WHIRLPOOL CORPORATION, MICHIGAN
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:THIES, EDWARD L.;REEL/FRAME:008845/0710
Effective date: 19971009
|Apr 4, 2002||FPAY||Fee payment|
Year of fee payment: 4
|Apr 3, 2006||FPAY||Fee payment|
Year of fee payment: 8
|Mar 8, 2010||FPAY||Fee payment|
Year of fee payment: 12